| Over the last few years, different communication schemes employing different frequency bands for transmit and receive signals as well as dual polarizations have been exploited for broadband applications. Traditionally, these schemes use reflector antennas with the signals collimated at the same focal point resulting in complex circuitry to extract the signals. Recently, the Communications Research Centre of Canada (CRC) demonstrated a dual band reflector-reflectarray antenna with independent focal points for each band. The antenna employed a Ka-band reflectarray with a Frequency Selective Surface (FSS) in place of the ground plane, which was then placed in front of a Ku-band parabolic reflector. The reflectarray antenna in which the ground plane has been replaced by a FSS has been called an FSS-backed reflectarray.;Based upon well-established reflectarray theory, the research utilized electromagnetic simulation software to analyze a FSS-backed reflectarray's unit cell performance. This analysis led to a design methodology that was used to design and fabricate several FSS-backed reflectarrays. These reflectarrays were cascaded to form a multi-band reflector antenna, which was then measured at each operating frequency in an anechoic chamber. Measurements demonstrated the practicality of this multi-band reflector antenna design. However, there were higher than expected losses, which were attributed to coupling between the reflectarrays.;This thesis expands upon the groundwork laid by CRC through the design of a multi-band reflector antenna employing several FSS-backed reflectarrays of different operating frequencies cascaded together. This particular design for the multi-band reflector antenna realizes several benefits: independent feed points, independent scan angles, lightweight construction and potential for multi-polarized applications. |
